AD/CL-600/115 - Air Driven Generator Strut

The AD is constructed around a small set of operationally significant concepts: applicability by serial number, part and assembly identification, conditional inspection triggers, inspection methodology and repeatability, re‑identification as an administrative closeout, and installation restrictions.

Applicability and identification: The AD applies only to Bombardier CL-600-2B16 (CL-604) aircraft with S/Ns 5408-5665 (Applicability). The starting action is an identification check of the ADG P/N and, where applicable, the ADG S/N and the S/N of the strut and generator housing assembly (Requirement 1). Note 1 explicitly permits the identification check to be done visually (which may require lowering the ADG) or by reviewing maintenance records (Note 1). The AD therefore relies on the combination of physical marking and maintenance record integrity to classify each ADG into action categories.

Conditional inspection triggers: The AD uses a decision tree in Requirement 1. If the installed ADG is the later P/N 604-90800-23, the strut wall thickness is deemed within specification and no further action is required. For ADGs with older P/Ns in the 761339 series, the AD requires different responses depending on S/N ranges: certain S/N thresholds (ADG S/N ≥ 2000, or S/N 0101-1999 when marked with symbol 24‑3) are treated as safe, requiring only re‑identification; other S/N combinations require an initial fluorescent penetrant inspection (Requirement 1.b.i-iii and associated subparts A and B).

Fluorescent penetrant inspection methodology: The AD mandates a fluorescent penetrant inspection of the ADG strut when S/Ns fall into the high‑risk ranges (Requirement 2). The required inspection and replacement procedures are to be performed in accordance with the Accomplishment Instructions of Bombardier Alert SB 604‑24‑017 Rev 1, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada (Requirement 2). Table 1 lists prior SB issues and Hamilton Sundstrand SB revisions which the AD accepts as meeting the intent of Requirement 2.

Repeat inspections and inspection after deployment: The AD requires repeat penetrant inspections before further flight after each scheduled ADG operational test (Requirement 3) and prescribes inspections following unscheduled ADG deployments: Requirement 4 triggers a visual and/or penetrant inspection after unscheduled in‑flight deployment, with specified deadlines (before further flight for visual, within 72 hours or 10 hours air‑time for penetrant in 4b). Requirement 5 requires a visual inspection after unscheduled on‑ground deployments.

Re‑identification closeout: Where P/N/S/N combinations indicate the strut wall thickness is within specification, the operator must re‑identify the ADG per Bombardier SB‑604‑24‑019 or approved Hamilton Sundstrand SB revisions (Requirement 6). After re‑identification, "no further action is required and compliance with this AD is complete" for those ADGs (Requirement 6 and Note 9).

Parts installation restriction: The AD forbids installation of specified ADGs (P/N 604-90800-1, -17, -19; Hamilton Sundstrand P/N 761339 series) into aircraft where the ADG S/N and the strut/generator housing assembly S/N fall into the risky ranges (ADG S/N 0101-1999 and assembly S/N 0001-2503), from the effective date of the AD (Requirement 7). An exception allows reinstallation of the same ADG onto the same aircraft if it was removed for non‑related purposes, such as maintenance or to gain access to other components (Requirement 7, Note 10).

References and cross‑document compliance: The AD anchors its inspection and re‑identification work to specific manufacturer service bulletins and notes that prior accomplishment in accordance with identified SBs (Bombardier and Hamilton Sundstrand) meets the intent of the AD (Table 1, Notes, and statements in Requirements 2 and 6). The AD also notes Transport Canada AD CF‑2009‑24 (Note 11), and requires that later SB revisions be approved by the Chief, Continuing Airworthiness, Transport Canada before they are used to meet the AD.

Timing and effectiveness: The AD specifies compliance windows for each requirement and becomes effective on 30 July 2009 (Compliance; Effective date). The timing structure mixes near‑term actions (within 400 flight hours or next scheduled ADG operational test) with immediate post‑event actions (before further flight or within short hour windows after an unscheduled deployment).

The AD therefore operationalises risk reduction through targeted inspection and administrative controls, deploying technical standards (fluorescent penetrant inspection as per SBs), serial‑number gating, and a parts installation bar to prevent introduction of potentially defective castings into the fleet.

Primary affected parties named in the AD are operators and maintainers of Bombardier CL-600-2B16 (CL-604) aeroplanes with Serial Numbers 5408 through 5665 (Applicability). The AD places duties on those responsible for airworthiness actions to perform identification, inspections, re‑identification and, as necessary, replacement of ADGs in accordance with the referenced Bombardier and Hamilton Sundstrand Service Bulletins (Requirements 1-7).

Operationally, the following roles bear the obligations and operational impact:

• Aircraft operators and owners of the specified CL-604 serial numbers, who must ensure the identification checks, inspections, re‑identifications and prohibited installations occur within the prescribed compliance windows (Compliance). Operators are the practical executors of the work and the parties who will incur labour, downtime and parts costs where replacement is required.
• Licensed maintenance organisations and continuing airworthiness personnel, who must perform the visual and fluorescent penetrant inspections in accordance with Bombardier Alert SB 604-24-017 Rev 1 or approved later revisions, and carry out re‑identification in accordance with Bombardier SB‑604‑24‑019 or accepted Hamilton Sundstrand SB revisions (Requirements 2, 3, 4, 5, 6 and Table 1). The AD explicitly allows identification by maintenance record review or by physically lowering the ADG for visual confirmation (Note 1).
• Parts suppliers and procurement officers, because Requirement 7 prohibits installation of certain ADG P/N and S/N combinations and identifies the later P/N 604‑90800‑23 (Hamilton Sundstrand P/N 1711405) as acceptable. The CL‑604 Illustrated Parts Catalog is also referenced as specifying that ADGs in the 761339 series should be replaced in future procurement by P/N 1711405 (Note 10).
• Regulatory bodies and international counterparts are indirectly implicated: the AD requires the use of Bombardier and Hamilton Sundstrand SBs and states that later revisions must be approved by the Chief, Continuing Airworthiness, Transport Canada (Requirements 2 and 6). The AD also refers to Transport Canada AD CF‑2009‑24 (Note 11), indicating coordination across national continuing airworthiness authorities.

Secondary impacts that the AD introduces include:

• Fleet availability: Operators whose aircraft fall within the S/N applicability must schedule identification checks and, where required, fluorescent penetrant inspections within tight timeframes (within 400 flight hours or next ADG operational test). Where ADGs must be removed and replaced, aircraft downtime and operational disruption will follow.
• Maintenance workload: Repeat inspections tied to scheduled ADG operational tests and post‑deployment events create recurrent maintenance tasks for specified ADGs (Requirement 3 and Notes 5-8).
• Supply and logistics: The prohibition on installing older P/N ADGs into aircraft with certain S/N ranges (Requirement 7) affects parts inventory strategy. The AD explicitly permits installing the acceptable P/N 604‑90800‑23 as a remedy, so procurement plans may need to source that P/N (Note 10).

The AD identifies the decision‑makers and executors: operators and their maintenance organisations decide how to sequence and resource the inspections and replacements, within the AD’s compliance windows; the Chief, Continuing Airworthiness, Transport Canada, decides whether later SB revisions are approved for compliance; and Bombardier/Hamilton Sundstrand provide the technical methods in their SBs which the AD references as mandatory compliance material where specified.

The AD does not name penalties, enforcement procedures, or audit mechanisms in the document text provided. It becomes effective on 30 July 2009 (Compliance), so affected operators and maintainers must have these processes and records in place by that date for compliance where applicable.

Duties imposed by the AD are explicit, structured and conditional on P/N and S/N outcomes. Key duties include:

1. Identification and classification (Requirement 1): Operators or maintainers must check the ADG P/N. If P/N 604‑90800‑23 is installed, no further action is required. For ADGs of the 761339 series (P/N 604‑90800‑1, ‑17, ‑19), further action depends on the ADG S/N and whether symbol 24‑3 appears on the identification plate. If certain S/N combinations are present (ADG S/N 0101-1999 without symbol 24‑3, and strut/assembly S/N 0001-2503), an initial fluorescent penetrant inspection is mandatory (Requirement 1 and Note 1).

2. Inspections and replacements (Requirements 2-5): Where required by the identification step, an initial fluorescent penetrant inspection of the ADG strut must be carried out and the ADG replaced if inspection reveals defects, following Bombardier Alert SB 604‑24‑017 Rev 1 (Requirement 2). Repeat penetrant inspections must be performed before further flight after each scheduled ADG operational test for ADGs that have been subjected to Requirement 2 (Requirement 3). After an unscheduled in‑flight ADG deployment, both visual inspection before further flight and a fluorescent penetrant inspection within 72 hours or 10 hours air‑time are required as specified (Requirement 4). After an unscheduled on‑ground deployment a visual inspection is required before further flight (Requirement 5).

3. Re‑identification (Requirement 6): Where the P/N/S/N checks demonstrate the strut wall thickness is within specification (for instance ADG S/N ≥ 2000, or ADG S/N 0101-1999 with symbol 24‑3, or assembly S/N ≥ 2504), re‑identification in accordance with the Accomplishment Instructions in Bombardier SB‑604‑24‑019 or approved Hamilton Sundstrand SB revisions is required. Once re‑identification is performed, the AD states "no further action is required and compliance with this AD is complete" for those ADGs (Requirement 6, Note 9).

4. Parts installation restriction (Requirement 7): From the effective date of the AD, it is prohibited to install specified ADGs (P/N 604‑90800‑1, ‑17, ‑19; Hamilton Sundstrand P/N 761339 series) into an aircraft if the ADG S/N is in 0101-1999 and the strut and generator housing assembly S/N is in 0001-2503. The AD allows reinstallation of the same ADG back onto the same aircraft if it was removed for non‑related purposes (e.g. maintenance access) (Requirement 7, Note 10).

Timing duties and compliance windows are set out in the Compliance table and must be observed: identification and initial inspections are within 400 flight hours or prior to next ADG operational test, repeat inspections before further flight after scheduled operational tests, and short windows for post‑deployment inspections (Compliance).

Rights and administrative points within the AD:

• Use of prior work: The AD permits that prior accomplishment of the fluorescent penetrant inspection conducted in accordance with the Bombardier SB or one of the specific Hamilton Sundstrand SBs listed in Table 1 meets the intent of Requirement 2. Similarly, certain revisions of Hamilton Sundstrand SB‑ERPS10AG‑24‑4 meet the intent of Requirement 6 (Table 1; Requirement 6). This permits operators to rely on earlier compliant maintenance activities without repeating them, subject to the AD’s stated acceptance of those SB revisions.
• Reinstall exception: Requirement 7 explicitly permits reinstallation of a removed ADG back onto the same aircraft if the removal was for non‑related purposes, which provides an operational exception where removal is not related to ADG defect mitigation (Requirement 7, Note 10).
• Approval of later SB revisions: The AD conditions acceptance of later SB revisions on approval by the Chief, Continuing Airworthiness, Transport Canada. This gives the approving authority the right to determine which later revisions will be acceptable for compliance (Requirements 2 and 6).

Administrative obligations implicit in the AD flow to the operator and maintenance organisations: maintain maintenance records that can be used to perform the identification checks (Note 1), ensure inspections and replacements follow the referenced SB instructions, and document re‑identification so that compliance can be demonstrated.

The AD does not specify enforcement powers, sanctions or penalty provisions in the text provided. It does specify an effective date (30 July 2009) and gives the issuer (CASA, via its delegate) and referenced external authority (Chief, Continuing Airworthiness, Transport Canada) roles in approving later SB revisions and cross‑acknowledging Transport Canada AD CF‑2009‑24.

The AD document as provided does not include express penalty provisions, monetary fines or a detailed enforcement mechanism within its text. The AD is presented as an instrument issued by the Civil Aviation Safety Authority (signed by James Coyne, Delegate, CASA) and becomes effective on 30 July 2009 (Compliance). It prescribes mandatory technical actions and compliance timeframes (Requirements 1-7; Compliance), which are obligations on the operators and maintainers of the specified CL‑604 aircraft, but the instrument itself does not detail the consequences of non‑compliance within the text provided.

Notable enforcement‑relevant features present in the AD are:

• Mandatory nature and effective date: The AD clearly states technical requirements and a definite effective date (30 July 2009). Mandatory ADs function as continued airworthiness instructions; in practice, an authority‑issued AD creates an enforceable requirement, but the AD text here does not elaborate enforcement steps or sanctions. It is therefore necessary, for any enforcement analysis, to treat the AD’s prescriptive content and timing as the operational command, even though the AD does not itself set out penalty mechanics.
• Documentation and traceability implications: The AD requires identification checks, inspections and re‑identification in accordance with specific SBs and within specified time limits (Requirements 1-6), which will create records that can be audited. The AD specifically allows identification via maintenance records or visual inspection (Note 1), thereby linking compliance evidence to recordkeeping that can be examined.
• Delegation and approvals: The AD references approval by the Chief, Continuing Airworthiness, Transport Canada for later SB revisions to be acceptable for compliance with specific Requirements (Requirements 2 and 6). That cross‑reference indicates involvement of another national continuing airworthiness authority in verification of acceptable methods, which could be relevant to cross‑jurisdictional enforcement or airworthiness validation.

Absent from the AD:

• There is no clause in the provided AD text that prescribes civil penalties, administrative sanctions or criminal penalties for non‑compliance. The AD likewise contains no procedural description of how CASA will notify operators of non‑compliance, suspend certificates, or otherwise enforce the directive.
• The AD does not specify audit frequency or the process by which CASA will verify completion of specific inspections, replacements or re‑identifications.

Analysts and compliance officers should therefore note that the AD imposes clear operational duties and compliance timeframes but leaves out explicit enforcement mechanics in the text provided. Where enforcement and penalties matter (for contracting, insurance, or operational risk), affected parties must consult the wider regulatory framework, CASA enforcement policy, and their regulatory compliance contacts to determine the practical enforcement consequences of non‑adherence to an AD. The AD itself documents the technical obligations, provides the SB references that must be followed, and specifies that it becomes effective on 30 July 2009.

The AD explicitly links its technical requirements to manufacturer service bulletins and to at least one other national continuing airworthiness action. These references create interdependencies between the AD and other administrative instruments and parts catalogues:

• Manufacturer Service Bulletins: The AD requires that inspections and replacements be done "in accordance with paragraphs 2.A., 2.C. and 2.D. of the Accomplishment Instructions in Bombardier Alert SB 604‑24‑017, Revision 1, dated 15 January 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada" (Requirement 2). Re‑identification must be done in accordance with Bombardier SB‑604‑24‑019, dated 1 October 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada (Requirement 6). The AD also lists Hamilton Sundstrand SB ERPS10AG‑24‑3 and later revisions in Table 1 as acceptable prior compliance. Those SBs therefore become the technical standard by which compliance with the AD is assessed, creating a relationship where the AD mandates adherence to technical instructions from the manufacturer and supplier.
• Transport Canada: The AD states that later revisions of referenced SBs must be "approved by the Chief, Continuing Airworthiness, Transport Canada" before being accepted for compliance with Requirements 2 and 6. The AD also refers directly to Transport Canada AD CF‑2009‑24 dated 19 May 2009 (Note 11). This indicates cross‑recognition and coordination between the Australian issuing authority and the Canadian continuing airworthiness authority, and that compliance may be satisfied by actions approved by Transport Canada. Practically, this gives Transport Canada a gatekeeper role for the acceptance of later SB revisions as compliant methods.
• Parts catalogue: The AD notes that the CL‑604 Illustrated Parts Catalog specifies that, for ADGs in the Hamilton Sundstrand P/N 761339 series, future procurement is to be an ADG with Hamilton Sundstrand P/N 1711405 (Note 10). This ties procurement choices to the parts catalogue and suggests that future supply-side decisions are to move to the later P/N, creating an interaction between the AD and the parts catalogue governing replacement parts.
• Manufacturer SB revisions and prior compliance: The AD accepts prior accomplishment of the fluorescent penetrant inspection conducted in accordance with the Bombardier or Hamilton Sundstrand SBs listed in Table 1 as meeting the intent of Requirement 2. Table 1 contains dates and revision levels for Bombardier Alert SB 604‑24‑017 and multiple revisions of Hamilton Sundstrand SB ERPS10AG‑24‑3 (Original, Rev 1, Rev 2, Rev 3 with dates). This cross‑validation creates an interaction where prior maintenance work, done under manufacturer instructions, is carried forward as satisfying the AD.

Legal and compliance practitioners should note that the AD relies on external technical documents and a foreign authority's approval for later revisions. In practical terms, the AD creates an obligation to use the specified SBs for technical compliance while deferring acceptance of later SB revisions to the Chief, Continuing Airworthiness, Transport Canada. This structure can generate administrative friction if an operator has access to different SB revisions or local maintenance processes. The AD also creates a link between recordkeeping (maintenance records may be used for identification per Note 1) and compliance demonstration, which interacts with statutory maintenance and recordkeeping duties that operators already hold under their operating licences and maintenance regulations (the AD itself does not recite those statutes, but it prescribes actions that will be evidenced in records).

The AD contains no express conflict‑resolution provision for differences between CASA and Transport Canada approvals. It simply conditions acceptance of later SB revisions on Transport Canada approval. The AD does not specify which national rules govern enforcement or penalties for non‑compliance; those matters are outside the AD text and would instead be determined under the broader civil aviation regulatory framework and CASA’s enforcement processes.

In short, the AD operates as a cross‑referencing instrument: it mandates compliance by imposing tasks that must follow manufacturer SBs, defers acceptance of later SB revisions to Transport Canada, and points to parts‑catalogue instructions for procurement direction. These linkages affect maintenance methods, procurement decisions and recordkeeping obligations across international and manufacturer documents.

The AD itself bears an issue designation AD/CL‑600/115 and a date code 8/2009, and it was signed by a CASA delegate on 19 June 2009. The AD states an effective date for compliance as 30 July 2009 (Compliance). Within the AD text, a number of service bulletin revisions and dates are cited; these constitute the document‑level amendment history relevant to the AD’s implementation because the AD expressly accepts certain SB revisions as meeting its intent. The following items are contained in the AD text:

• Bombardier Alert SB 604‑24‑017: The AD requires inspections be carried out "in accordance with paragraphs 2.A., 2.C. and 2.D. of the Accomplishment Instructions in Bombardier Alert SB 604‑24‑017, Revision 1, dated 15 January 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada" (Requirement 2). Table 1 lists Bombardier Alert SB 604‑24‑017 Original Issue dated 6 May 2005 as well.
• Hamilton Sundstrand SB ERPS10AG‑24‑3: Table 1 lists multiple versions and dates of this SB as meeting the intent of Requirement 2 if previously performed. Table 1 entries are:
  • Hamilton Sundstrand SB ERPS10AG‑24‑3 original issue dated 14 April 2005.
  • Revision 1 dated 19 April 2005.
  • Revision 2 dated 14 November 2006.
  • Revision 3 dated 12 March 2009. The AD states that prior accomplishment of the fluorescent penetrant inspection conducted in accordance with either Bombardier SB 604‑24‑017 or one of the SBs listed in Table 1 meets the intent of Requirement 2 (Table 1 note).
• Hamilton Sundstrand SB ERPS10AG‑24‑4: For re‑identification (Requirement 6), the AD expressly accepts re‑identification conducted in accordance with Revision 2 (dated 14 September 2007), Revision 3 (dated 12 February 2008) or Revision 4 (dated 30 April 2009) of Hamilton Sundstrand SB ERPS10AG‑24‑4 as meeting the intent of Requirement 6.
• Bombardier SB‑604‑24‑019: Re‑identification must be carried out "in accordance with the Accomplishment Instructions in Bombardier SB‑604‑24‑019, dated 1 October 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada" (Requirement 6).

The AD therefore integrates a set of manufacturer SB revisions spanning 2005-2009 into its compliance matrix. The AD’s text does not itself contain an internal amendment log beyond referencing current and prior SB revisions; it does not list any internal amendments to the AD after the signature date. The AD does, however, make explicit that later SB revisions will be acceptable only with approval from Transport Canada’s Chief, Continuing Airworthiness (Requirements 2 and 6). This gives a mechanism for amendment of the technical method via subsequent SB approvals, but the AD itself remains the controlling instrument unless replaced or superseded by a later AD.

Finally, the AD notes that Transport Canada AD CF‑2009‑24 dated 19 May 2009 "refers" (Note 11). This indicates a contemporaneous foreign AD that interacts with or parallels CASA’s AD; the AD does not state procedural linkage beyond noting that Transport Canada’s AD exists. The AD does not contain a revision history for itself in the text provided, nor does it list any superseding or repealing ADs.

Practically, compliance managers should track the referenced SB revision dates, and the approval status from Transport Canada if intending to use later SB revisions to satisfy the AD. The AD’s acceptance of prior SB‑based work removes the need for repeated inspections where those SBs were already applied, but operators must maintain records proving prior compliant accomplishment.

The AD text provided contains no references to litigation, court decisions, or administrative appeals. There are no cases, determinations, or legal proceedings named in or appended to the document. The document is an administrative airworthiness directive issued by the Civil Aviation Safety Authority and signed by a delegate; within the AD itself there is no litigation history, no reference to appeals against the AD, and no mention of judicial or administrative proceedings concerning its content or enforcement.

Where readers require the litigation context,such as precedents on enforcement of ADs, challenges to ADs, or disputes about compliance methods,this AD does not supply those materials. The AD does reference a Transport Canada AD (CF‑2009‑24) and multiple manufacturer service bulletins and revisions (Bombardier and Hamilton Sundstrand SBs), but it does not report any legal disputes, review decisions, or litigation records pertaining to these instruments.

For legal practitioners, the absence of litigation references in the AD means the document stands purely as an administrative technical mandate in the material provided. Any enquiry into litigation history would require consultation of external legal databases, CASA enforcement records, or court registries; those sources are not part of the AD text and are not cited here. This AD text should therefore be treated as a technical instrument without documented litigation narrative in the source.

Several operational and compliance pitfalls are embedded in the AD’s wording and structure. Those likely to cause misinterpretation or administrative error are:

1. Serial number logic and symbol 24‑3: Requirement 1 uses a layered S/N logic. For ADGs with P/Ns in the 761339 series, the AD requires checking both the ADG S/N and whether symbol 24‑3 is present in the S/N block of the identification plate. An ADG S/N of 0101-1999 without symbol 24‑3 triggers further checks of the strut and generator housing assembly S/N and potentially a fluorescent penetrant inspection (Requirement 1.b.iii). Misreading the symbol requirement or mis‑recording the S/N could incorrectly classify an ADG and either create unnecessary inspections or miss required ones.

2. Visual identification may require lowering the ADG: Note 1 states that Requirement 1 may be conducted visually, which requires lowering the ADG, or by checking maintenance records. Practically, if maintenance records are incomplete or ambiguous, the maintenance task may expand to include mechanical lowering and additional labour and downtime; this contingency needs prior planning.

3. Multiple time windows and event triggers: The AD contains a mix of compliance timeframes,within 400 flight hours or before the next scheduled ADG operational test, before further flight after unscheduled events, and within 72 hours or 10 hours air‑time for certain penetrant inspections (Compliance; Requirements 3-5). Failure to respect the shortest relevant window (for example, performing a penetrant inspection after an in‑flight deployment beyond 72 hours) would technically be non‑compliant.

4. Repeat inspections linked to scheduled operational tests: Requirement 3 mandates repeat fluorescent penetrant inspections before further flight after each scheduled ADG operational test for ADGs previously inspected under Requirement 2. If operators are not tracking which ADGs are in the "inspected under Requirement 2" cohort, they may miss the need for these repeat checks.

5. Reinstallation exception scope: Requirement 7 allows installing a removed ADG back onto the same aircraft if it was removed for non‑related purposes. The AD does not define "non‑related purposes" further, and operators could face disputes about whether a removal was related to ADG issues. Clear documentation of the reason for removal will therefore be essential to rely on this exception.

6. Acceptance of prior SB‑based inspections: The AD accepts prior accomplishment of the fluorescent penetrant inspection according to SBs listed in Table 1. However, the reverse implication is that if prior inspections were done in a manner not matching the listed SB revisions, the AD may still require new inspections. Operators must verify the exact SB revision used previously and document it to avoid redundant work.

7. Parts installation prohibition versus operational exigencies: Requirement 7 prohibits installation of certain ADGs into aircraft when P/N/S/N/assembly S/N conditions are met. This restriction could create operational headaches if spares stock includes ADGs in the prohibited ranges. Operators must segregate inventory and ensure procurement shifts to the acceptable P/N 604‑90800‑23 to avoid inadvertent installation.

8. Cross‑authority approvals: The AD accepts later SB revisions only if approved by the Chief, Continuing Airworthiness, Transport Canada (Requirements 2 and 6). If an operator wishes to follow a later SB revision approved elsewhere (for instance, by Bombardier but not yet by Transport Canada), the AD will not accept that method unless Transport Canada approval is present. This can create administrative delays when SB updates are released but not yet approved by Transport Canada.

9. Documentation as proof of compliance: Note 1 permits reliance on maintenance records for initial identification. If records are incomplete or inconsistent across jurisdictions, the AD places the onus on operators to create sufficient documentary proof. Failure to do so will likely lead to rework.

10. Effectivity date and retroactive work: The AD becomes effective on 30 July 2009. The AD accepts prior inspections under specified SB revisions as meeting its intent, but only those explicitly listed. Operators with maintenance work performed under other processes may need to re‑inspect or re‑do work to satisfy the AD’s explicit listed standards.

These "gotchas" point to practical compliance risks: misclassification due to S/N logic, administrative friction because of cross‑jurisdictional SB approvals, potential spares shortages or inventory management issues, and the need to maintain accurate, traceable records to defend exceptions (e.g. re‑installation). Operators and maintenance organisations should build checklists, S/N crosswalks and record templates to avoid these issues.

Compliance with this AD requires an organised, documented workflow that follows the AD’s decision tree and timing windows. The steps below map the AD’s Requirements and Notes into concrete operational tasks. All steps should be documented in the aircraft’s maintenance records, as Note 1 allows reliance on records for identification.

1. Identify applicability:

   • Confirm aircraft Serial Number is within Applicability: CL‑600‑2B16 (CL‑604), S/N 5408 through 5665. If outside this range, the AD does not apply as written (Applicability).

2. Perform Requirement 1 (Identification Check) within its compliance window:

   • Timing: For Requirement 1, perform within 400 flight hours or before the next scheduled ADG operational test after the AD effective date (Compliance).

   • Check the installed ADG P/N.

     • If P/N = 604‑90800‑23 (Hamilton Sundstrand P/N 1711405): the AD states the strut wall thickness is within specification and no further action is required; proceed to completion for that ADG (Requirement 1.a).
     • If P/N is 604‑90800‑1, ‑17 or ‑19 (Hamilton Sundstrand P/N in the 761339 series): check the ADG S/N and the identification plate for symbol 24‑3.
       • If ADG S/N ≥ 2000: strut wall thickness is within specification; re‑identification required (Requirement 1.b.i).
       • If ADG S/N in 0101-1999 and symbol 24‑3 is present in the S/N block: strut wall thickness within specification; re‑identification required (Requirement 1.b.ii).
       • If ADG S/N in 0101-1999 and symbol 24‑3 is not present: check the S/N of the strut and generator housing assembly (location per Figure 1, Sheet 1 of Hamilton Sundstrand SB ERPS10AG‑24‑3) and then:
         • If strut/assembly S/N 0001-2503: fluorescent penetrant inspection required (Requirement 1.b.iii.A → Requirement 2).
         • If strut/assembly S/N ≥ 2504: strut wall thickness within specification; re‑identification required (Requirement 1.b.iii.B → Requirement 6).

   • Practical notes: Identification can be done visually (may require lowering the ADG) or by maintenance records (Note 1). If records are used, ensure they identify exact P/Ns, S/Ns and symbol markings.

3. If Requirement 2 applies (Initial Fluorescent Penetrant Inspection):

   • Timing: Within 400 flight hours or before next scheduled ADG operational test after the AD effective date (Compliance).
   • Method: Conduct the inspection and replace the ADG as necessary "in accordance with paragraphs 2.A., 2.C. and 2.D. of the Accomplishment Instructions in Bombardier Alert SB 604‑24‑017, Revision 1, dated 15 January 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada" (Requirement 2).
   • Acceptance of prior work: If a fluorescent penetrant inspection has already been conducted in accordance with Bombardier SB 604‑24‑017 or one of the Hamilton Sundstrand SBs listed in Table 1, that prior work meets the intent of Requirement 2.

4. If Requirement 3 applies (Repeat Fluorescent Penetrant Inspections):

   • Timing: Before further flight after each scheduled ADG operational test (Requirement 3).
   • Method: Use the same SB instructions referenced in Requirement 2 (Bombardier SB 604‑24‑017 Rev 1 or approved later revisions).
   • Note: Requirement 3 is required for each ADG inspected under Requirement 2 (Note 5).

5. After unscheduled ADG deployments:

   • For in‑flight unscheduled deployment (Requirement 4):
     • 4a Visual inspection: Before further flight, visually inspect ADG strut and replace ADG if necessary per paragraphs 2.A., 2.B. and 2.D. of Bombardier Alert SB‑604‑24‑017 Rev 1. No further action if replaced by P/N 604‑90800‑23.
     • 4b Fluorescent penetrant inspection: Within 72 hours or 10 hours air‑time (whichever comes first) after unscheduled in‑flight deployment, perform penetrant inspection and replace ADG if necessary per paragraphs 2.A., 2.C. and 2.D. of Bombardier Alert SB‑604‑24‑017 Rev 1. Note 7 clarifies that 4a is not required if 4b is performed before further flight.
   • For on‑ground unscheduled deployment (Requirement 5):
     • Visually inspect ADG strut and replace ADG if necessary per Bombardier SB paragraphs 2.A., 2.B. and 2.D.; this must be done before further flight (Requirement 5). If replaced by P/N 604‑90800‑23, no further action is required.

6. Re‑identification (Requirement 6):

   • Timing: For ADGs requiring only re‑identification (as determined in Requirement 1), do so within 400 FH or before next scheduled operational test, whichever comes first (Compliance).
   • Method: Re‑identify per Bombardier SB‑604‑24‑019 dated 1 October 2007 or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. Re‑identification conducted per Hamilton Sundstrand SB‑ERPS10AG‑24‑4 Revision 2-4 (dates listed in AD) also meets the intent.
   • Completion: Following re‑identification, the AD states no further action is required and compliance with the AD is complete for that ADG (Requirement 6, Note 9).

7. Parts installation control (Requirement 7):

   • From the AD effective date (30 July 2009), do not install ADGs with P/N 604‑90800‑1, ‑17 or ‑19 (Hamilton Sundstrand P/N 761339 series) on any aircraft if the ADG S/N is in 0101-1999 and the strut/assembly S/N is 0001-2503.
   • Exception: It is permitted to reinstall the same ADG onto the same aircraft if it had been removed for non‑related purposes (e.g. to gain access for unrelated maintenance tasks). Document reason for removal and reinstallation carefully to support this exception (Requirement 7, Note 10).
   • Procurement note: The AD notes that the CL‑604 Illustrated Parts Catalog specifies future procurement for ADGs in the 761339 series should be for P/N 1711405 (Note 10).

8. Recordkeeping and evidence:

   • Record the identification checks, S/N readings, presence/absence of symbol 24‑3, inspection results, replacements, re‑identification actions and any deployment events. Note 1 permits using maintenance records for identification; the AD accepts prior SB‑compliant inspections listed in Table 1 as meeting Requirement 2. Maintain copies of the SBs and the specific revision used for the work.

9. Liaison with authorities and SB approvals:

   • If using later SB revisions than those expressly listed, ensure those revisions are approved by the Chief, Continuing Airworthiness, Transport Canada as required by the AD (Requirements 2 and 6). Maintain written evidence of any such approvals.

10. Operational planning:

    • Because some tasks require lowering the ADG for visual checks, plan for hangar time and the necessary maintenance resources. When replacement is necessary, ensure availability of acceptable replacement P/N 604‑90800‑23 (P/N 1711405) or ensure the ADG to be installed does not fall under the prohibited S/N ranges.

In summary, compliance requires following the stepwise identification process in Requirement 1, applying the appropriate inspection or re‑identification pathway, adhering to the specific SB instructions referenced, meeting the AD’s timing windows and documenting every step. Where uncertainty exists about SB revision acceptability, obtain the required Transport Canada approval. The AD provides explicit exceptions for prior compliant SB work and for limited reinstallation on the same aircraft; these exceptions must be supported by record evidence.